Collmenter (4-1), allowed three hits, struck out five and walked one, improving to 3-1 with a 1.23 ERA in five starts since he entered the rotation last month.

David Hernandez and Joe Paterson each got three outs to complete the three-hitter, Arizona's 17th victory in 21 games. The Diamondbacks (32-26) began the night only a half-game out of first in the NL West.

Yunesky Maya (0-1), making his second start of the season, allowed four runs and six hits in 4 1-3 innings for the Nationals.